Best available cop



BEST AVAILABLE COP Oct. 23, 1928.

J. A. MEARS SOUND REPRODUCER' Filed Sept. 16, 1925 I5 Sheets-Sheet l glvwcntoz Jo n 5h Ar ch/ba/d means a fl BEST AVAiLABLE COP UUUUUUUUUUUUU ER BEST AVALABLE COP Oct. 23, 1928. 1,688,730

J. A. MEARS SOUND REPRODUCER Filed Sept. 16, 1925 s Sheets-Sheet 3 Jose l) flrcbiba/d mead.

attomeq Patented Get. 23, 1928.

BEST AVAILABLE COP UNITED STATES PATENT QFFlC-E.

JOSEPH ARCHIBALD HEARS, OF NEW YORK, N. Y., ASSIGNOR TO WIRED RADIO, INQ,

OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SOUND REPIRQDUCEB.

Application filed September suchnianner that they may be shipped in knocked down position within a small compass and: assembled by a customer into a completed instrument for reproduction of electrical vibrations.

Still another objectof my inventionis to provide aloud speaker having a double cone plaited sound reproducing diaphragm encIo's iiig -a sound "chamber, the volume of which, may be readily changed and'the tension upon'bo th cone area's of the diaphragm correspondinglfchanging to select values, which give thefmofst pleasing sound re-.

v ll b mer i iifi t o i'. r sents to h accomp ng.

1 Figure [1! ,shows' a .strip of sheet inaterial which is employed in theconstructi onof the diaphragm? Fig.1 2 shows the sheet material ofTigil 'folded into adouble strip for the purpose of constructing the 'double plaited cone;'Fig 3 is a cross-sectional view of the folded's triptaken on line 33 of Fig. 2; Fig.4 is a perspective view of the double folded strip from which the double cone diaphragm is folded'; Fig. 5 is an end view of theplaited material of the diaphragm where it has been opened out flat and the ends of thestrip broughttogether to form a cylinder; Fig. 6 is a plan view looking down upon the cylindrical construction of the diaphragm; Fig. 7 indicates the diaphragm with its ends gathered in the process of folding into a completed diaphragm which has been represented more clearly in Fig. 8; Fig.

9 represents a front view of the completed diaphragm; Fig. 10 shows a cross-sectional view of the diaphragm assembled with the electromagnetic actuating mechanism; Fig. 11 is a fragmentary view illustrating the ad- 16, 1925 Serial No. 56,671.

justable feature of the diaphragm construc- A tion by which the volume within the sound chamber varied; and Fig. 12 is a d1agram matic view showing the parts of the, electromagnetic sound reproducer folded into' a 69 small compass for the process of shipment.

Referring to the drawings in detail, refercnce character 1 indicates a strip of flat sheet material from which the sound reproducing diaphragm is formed. The flat sheet mate-i.

rial contains an end portion 2 for thepurpose of forminga lap joint as will be more fully described hereinafter. The strip 1" arranged to be folded longitudinally along dot:

ted line 3 to a double thickness consisting of 7 surfaces 4 and 5 in Fig. 2; In the double folded positionof Fig. 3 thestrip 1 has one surface 4 folded directly in'c ontac-t withits, opposite surface 5. The double folded strip:

l-isf then folded inalternate directionslfornr 1.

ing plaits 6 along the strip as represented'in Fig. 3%.. The doublefolded plaited strip .--of Fig. 4 is thenfopened'. out flat and the {ends brought together utilizingthe portion 2;,for

forming a lap jointwith theopposite end ot the strip atT. The strip 'now forms Substaii; tially a cylinder whichis more clearly rep resented in plan viewin-Fighfi. {The ends 8 and 9 of thecylindrical plaited-strip are neat. gathered as represented in Fig. 7 and pushed inwardly to completethe double folded cone as represented in Fig. 8in suclrmannerthat the diaphragm has. the appearance front elevation as representedgin Fig: 9., a

In order to support the sound reproducing diaphragm a stand which may be readily as-; sembled or disassembled is provided as shown in Fig. 10. v The stand includes a base portion; 10, an angularly disposedupright .lland an.

electromagnetic driver 'which is-contained within a housing 12. The'diaphragmlis shown as having the plait 6 in each side of; the foldset and 5. The inner edges ofthe; cone portions of the diaphragm are supported by guide washers. The inner edges of the cone portion 4 fit between guide washers 14' and 15 on cylindrical member 16 while the inner edges of the cone portion 5' representedin Figures 8 and 9 at reference character 9' fit between washers 17 and 18 which are carmember 19 cooperate in such manner that the 1 chamber which volume ma sides of the double cone can be moved toward or away from each other to vary the volume enclosed by the cones. Where it is desired to reduce the volume of the sound chamber enclosed by the double cone the member 19 1s threaded into cylindrical member 16, the cone portion 5 assuming dotted line position 5 at the same time that washer members 17 and 18 assume dotted line positions 17 and 18 respectively. Sound vibrations are imparted to the entire diaphragm through link 21 which carries the adjustable member 16 and 19 on one end thereof. The construction of the sound reproducer is such that the parts may be disassembled and packed within a small area as represented in Figure 12 where the upright 11 has been removed from the aperture 23 in the base 10 and laid along the base 10 in contact therewith, while the diaphragm is shown folded into a compact rectangular area indicated at 22. The process of assembly of the diaphragm is extremely simple as the folded diaphragm 22 is readily unfoldedand mounted uponthe adjusting devices 16 and 19. I

It will be observed that the sound reproduction of the diaphragm-may be governed by selecting a particular volume for the sound be readily changed by means of the adjusting device heretofore described.

While I have described my invention in certain particular embodiments, I desire that it'be understoodthat modifications may be made and that I intend no' limitations upon the invention other than those imposed by the scope of the appended claims.

What-I claim and desire to secure by LettersPatent of the UnitedStates is asifol- 1. A sound reproducing diaphragm comprising a 'single'sheet of 1 plaited material folded into a do'uble'cone with the peripheral edges of the bases thereof formed integral with each other for enclosing a sound chamber' between the surfaces of the double cone an'dmeans for adjusting the distance between the apexes of the cones for selecting a desired volume of sound chamber between said cones.

'2. -A- sound reproducing diaphragm comprising a pair'- or plaited cone surfaces with their bases adjacent each other and their apexes opposite each' other for enclosing'a sound chamber between said plaited cone surfaces and means for adjusting the distance between the apexes of said cone surfaces.

3. A sound reproducing 'diaphragmromprising a pair of plaited surfaces diverging in opposite directions from each other, for enclosing a sound chamber between said plaited surfaces, and means for varying the angular degree of divergence of said surfaces for selecting the volume of the sound chamber enclosed'by said surfaces.

4. A sound reproducing diaphragm comprising a pair of plaited cone surfaces with their bases adjacent each other and their apexes opposite each other, a pair of screw threaded members each provided with closety adjacent flangesfori. guiding the centrally disposed inner peripheral edges of each of said cone surfaces toward or away from each other for adjusting the volume of the sound chamber between said cone surfaces.

5. A sound reproducing diaphragm comprising a pair of plaited surfaces diverging in opposite directions from each other and providing an enclosed sound chamber between the plaited surfaces, a pair-of screw. threaded members cooperating one with the other and each having guiding flanges thereon with the centrally disposed inner peripheral edges of each of said plaitedsurfaces disposed between said flanges wh'erebylthe angular degree of divergence of said surfaces may be varied for selecting the-volume of the sound chamberenclosed by. said surfaces.

6. A diaphragm comprising a pairofhoh lowcones, v having plaite'dfsurfaces formed from a single sheet of ;.material with'fithe plaited surfaces disposed atacute angles to each other, said conesbeing attached to each other around the periphery. of-',.t heir bases and with their apexesseparated,landzvariable in position relative, to eachother to form an air chamber adjustable infvolnme for'zthe reproduction of tones over a. ,br0ad..ran'ge of musical notes. j v j 7. A sound; reproducing 'diaphragmlcom prising a pair of hollow, cones, at leastone. of

said cones having a fluted surface: with. the bases'there'o'f adjacent to each" other and their apexes separated-to ,form '.a. sound chamberQQand means forf ,variably selecting a and the distance between Isaidnp'exes.

8. A sound reproducer comprising'japair of diaphragms. arranged substantiallyin the form of cones with thebasesQthereof'jnte grally connect-ed.and the surfaces of at least. one of said eones'jbeing plaited, the .apexes of said'cones being joined together by' aneans arranged to impart sound vibrationsto said diaphragms,-.said means operating to selectively iii; the special relationof'said diaphragms at the apex'e's thereof. I

9. A sound reproducer comprising-apair of screw threaded members arranged to :be adjusted one with respect to the other along the same axis, each of said members carrying a set of annular flanges, a pair ofcoexten sive plaited surfaces diverging from a common periphery and having their inner edges secured between each of-said sets of annular flanges whereby said screw threaded members may be adjusted one with respect to the other for varying the angular relationship of said plaited surfaces.

10. A loud speaker repro'ducer comprising a pair of cone shaped surfaces having radial plaits extending throughout their area, from a position adjacent a central axis, said cone devices for egaging the inner ends of each of shaped surfaces having the radial plaits the plaits formed on said conical surfaces at thereof joined at the outer periphery of said a position adjacent said central axis, and surfaces, a double screw member located cenmeans for imparting sound vibrations to 5 trally of said surfaces said double screw said screw threaded devices.

member consisting of a pair of screw threaded In testimony whereof I my signature. devices, one entering the other, apair of flanges carried by each of said screw threaded JOSEPH AROHIBALD MEARS. 

